Means for actuating soot blowers



Nov. 1, 1955 Filed May l2, 1950 R. J. GLINN ET AL MEANS FOR ACTUATING SOOT BLOWERS 2 Sheets-Sheet l HUE D NV 1, 1955 R J. GLINN ET A1.

MEANS FOR ACTUATING SOOT BLOWERS 2 Sheets-Sheet 2 Filed May l2, 1950 .n @I MV1 United States Patent O MEANS FR ACTUATING SOOT BLOWERS Roy J. Glinn and Percy G. Handoll, London, England, assignors to Diamond Power Specialty Corporation, Lancaster, Ohio, a corporation of Ohio Application May 12, 1950, Serial No. 161,636

4 Claims. (Cl. 15-317) This invention relates to fluid heater cleaners. Generally in large boilers the cleaners for the heating surfaces subject to deposits from the furnace gases are power actuated, remotely controlled and arranged to operate automatically in predetermined sequence, and the control gear for the cleaners of a vapor generating and superheating unit of a modern power station tends to be undesirably complicated and the reduction in the first cost and the lessening of the maintenance work on such gear are problems of some importance. An object of the invention, therefore, is to enable control gear for effecting automatic and sequential operation of a number of individually power driven cleaners, including at least one cleaner of the type comprising a blower element arranged to be projected for operation from an inoperative or retracted position and to be rotated for the purpose of varying the direction of discharge of cleaning fluid to be simplified.

Normally the distances of the tube surfaces to which the discharge of cleaning fluid from the cleaner is directed in the cleaning of tube surfaces of a tube bank Vary with the angular positions of the blower element as the latter rotates. As a consequence, when a blower element rotating at constant speed is arranged to be directed sufflciently long towards the more remote surfaces in order to clean them adequately, the tube surfaces nearer the blower element may receive cleaning huid for a very considerably longer time than they require. Another object of the invention is to reduce the time necessary for a cleaning operation and to economize in the cleaning fluid.

In a cleaning system for a vapor generating and superheating or the like unit, some of the cleaners may be of the type comprising a blower element arranged to be projected for operation from an inoperative or retracted position and to be rotated for the purpose of varying the direction of discharge of cleaning fluid, while other cleaners may be of the kind in which the blower element is rotatable but non-retractable and a further object of the invention is the provision of actuating means for effecting oscillation of a blower element adapted to be operated by unidirectional driving means which means is applicable whether the element is retractable or non-retractable.

The present invention includes a fluid heater cleaner comprising a blower element arranged to be projected for operation from an inoperative or retracted position and to be rotated for the purpose of varying the direction of discharge of cleaning fluid, comprising an operating spindle, first actuating means continuously coupling the spindle to the blower element and adapted through unidirectional rotation of the spindle to effect projection and retraction of the blower element and second actuating means also coupling the spindle to the blower element and adapted to effect rotation of the element.

The invention also includes a fluid heater cleaner comprising a rotary blower element, an operating spindle and actuating means adapted upon unidirectional rotation of the spindle in one direction to effect oscillation of a blower element about its longitudinal axis, the actuating means ICC including a crank device and a rack connected with the crank device and in engagement with a pinion in driving relationship with the blower element.

The invention moreover comprises apparatus for so operating a fluid heater cleaner that a rotatable blower element is arranged to direct cleaning fluid over an angle of rotation thereof towards fluid heater surface regions to be cleaned whose distances from the blower element increase towards the extremities of the angular movement of the blower element over which cleaning fluid is discharged, means being provided for running a power device unidirectionally and driving the blower element by the power device to effect oscillation of the blower element about its longitudinal axis at variable angular velocity which, during an angular movement of the blower element from one extreme angular position to the other, increases while the rate of decrease of the distances from the blower element to the regions to which the cleaning fluid is directed, with respect to the angular positions of the blower element, is large and decreases while the rate of increase of the distances from the blower element to the regions to which the cleaning fluid is directed, with respect to the angular positions of the blower element, is large.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure l is a cross-section of a soot blower longitudinally of the blower tube, on the line 1-1 of Fig. 2, showing the blower tube in fully retracted positions;

Fig. 2 is a plan view of the soot blower;

Fig, 3 is a longitudinal cross-sectional view similar to Fig. l, but showing the blower tube in fully advanced position, and showing a forked lever arm 27, stirrup piece 29 and a sheave-like member 23, hereinafter referred to in outside View instead of in section, and having parts removed to show the arrangement of other members;

Fig. 4 is an elevation of the soot blower looking forwardly in the direction of the aXis of the blower tube, with the lower part thereof in section on the line [F4 of Fig. 3;

Fig. 5 is a sectional elevational view similar to the lower part of Fig. 4, but showing the parts in other relative positions;

Fig. 6 is an elevation of the forked lever arm 27 and the stirrup piece 29, shown separately from the rest of the soot blower; and

Fig. 7 illustrates the nature of the angular motion of the blower tube of the described soot blower, assuming drive at constant speed as by electric motor driving means.

Referring to the drawings, an electric motor 1 is arranged so that unidirectional rotation of the shaft thereof effects projection and retraction of a soot blower tube 2 tted with a four nozzle blower head 3, and also effects oscillatory rotation of the blower tube.

The electric motor is mounted on a platform 4 at one side of a bracket 5 to a lower limb 6 of which an extension 7 from the platform is bolted. An operating spindle 8 to whichl are keyed both a single pitch worm 9 and a pinion 10 is in line with and coupled to the shaft of the electric motor and is journaled within a casing v11 secured at the rear end of the bracket 5.

Within and journaled in the casing and engaging with the worm 9 is a worm wheel 12 having eighteen teeth, upon the spindle of which is mounted, on an end nearer the bracket 5, a crank 13 outside the casing. The movable end of the crank is connected to an end of a connecting rod 14, the other end of which is connected to the movable end of a rockable arm 15.

The bracket 5 is secured at the rear side of a forging 20 within which is housed the main steam valve 21 controlling the ow of steam to the blower tube, and

an Aactuating spindle 22 formed integral with .the blower tube 2 extends in a passage through the forging 20, and extends rearwardly in the space between an upper limb 16 and the lowe-r v'lim-b 6 of .the bracket .5, where it is provided with a sheave-like member 23 having va front projection 24 in the form .of a .collar 'having a cylindrical surface .and a rear projection 25. The arm is secured to a spindle .26 arranged in bearings in the bracket upper limb 16, and mounted on the spindle 26 for rotation therewith is a forked lever arm 27, the forks of which are -provided with trunnions 28 extending towards one another and fitting into respective holes in the two lower ends of a saddle piece 29. The saddle piece 29 spans the spindle 22 and the two lower -ends of the saddle piece are adapted to slide between the opposing faces of the projections 24 and 25. When the blower tube is Vin the Aforemost position (Fig. 3), the forked lever arm 27 makes an angle of about 50 with the blower tube axis and when the blower tube is in the rearmost position (Figure l), the forked lever arm 27 makes an angle of also `about 50 with the blower tube axis.

The pinion 10 on the operating spindle 8 has twenty teeth, and engages with a spur wheel 30 -of sixty teeth. The spur wheel 30 is arranged within and is -journaled in the casing 11 and acts as a crank, at .one location on the spur wheel an end of a rack 31 being rotatably secured, which is arranged so that the teeth thereof engage with the teeth of a second pinion 32. The second pinion 32 is formed with forward and rearward extensions 33 and 34, respectively, which fit rotatably within respective forwardly and rearwardly projecting hub positions 35 and 36 of a guide member 37. The hub positions 35 and 36 fit rotatably within suitable bearings in the casing 11, arranged so that the second pinion 32 is coaxial with the blower tube 2. The actuating spindle 22 extends rearwardly of the sheave-like member 23 with which it is provided and slidably fits within the forward extension 33 of the second pinion 32, and keys are provided which fit within keyways 41 in the actuating spindle 22 and lit slidably within keyways 42 in the second pinion 32.

The guide member 37 maintains engagement between the rack 31 and the second pinion 32 by means of a roller 43, consisting of a ball-bearing, which is arranged to bear on the side of the rack opposite to the rack teeth in countering the thrust on the rack in a direction away from the second pinion. The guide member 37 is formed in two similar halves suitably secured together, each of which is formed with a key 44 engaging within a corresponding keyway 45 in the corresponding side of the rack.

When the blower tube is in its rearmost position (Fig. l), the rearmost extremity 46 of the actuating spindle 22 is arranged to engage with the operating member 47 of an electric limit switch 48. When the blower tube is sufficiently projected, the front projection 24 of the sheave-like member 23 serves to raise a tappet 49 which actuates a relay valve 50 which effects opening of the main valve 21 and thereby admits steam to the blower tube 2 for emission through the nozzles of the blower head 3.

The tappet 49 carries on an end nearer the blower tube a semi-enclosed ball 51 rotatable in any direction, and is slidably mounted with a forward inclination in a boss 52 in the bracket upper limb 16 for movement away from or towards the axis of the blower tube. At its end further from the axis of the blower tube the tappet 49 contacts a sector-shaped lever 53 against which is pressed, by means of a biasing spring 54, the outer end of the spindle 55 of the relay valve 50. The construction of the relay and main valves and 21 is almost identically the same as the construction of the relay and main valves of the fluid heater cleaner described and illustrated in British Patent No. 533,609. Thus, the

spindle is parallel to the blower tube and the relay valve 50 is mounted in a cover plate 56 to the forging 20. The relay valve 50 is arranged for controlling the escape of steam through an escape passage from a space 61 at a side of a piston 62 which is secured to the spindle 63 of the main steam valve 21, of which it controls the opening and closing by sliding within a fixed cylinder v64 held in position on the forging by the cover-plate 56. Before steam from the space 61 can obtain access to the relay valve 50, it has to flow through a passage 65 into which, when the main valve is open, projects a plunger 66 at the end of the spindle 63. The arrangement of the piston 62 in the cylinder 64 allows for a certain steam leakage between the sides of the piston. The main valve spindle 63 is biased towards the closed position by a helical spiral spring 67. The steam for the blower tube is led to the interior of the forging 20 by a suitable connection .(not shown), flows, when released by the main valve 21, into a space outside the .front part of the actuating spindle 22, from which space it is prevented from escaping by a packing 68 and sliding joint 69 provided between the blower tube 2 and a tubular extension 70 to the forging 20, and .enters the interior of the blower tube through ports 71.

When the electric motor is started, the operating spin kdle 8 revolves and turns both the worm 9 and the .pinion 1-0. The worm 9 causes the worm wheel 12 to rotate, which by means of the crank 13 and connection rod 14 rocks the arm 15 and therewith the forked lever arm 27, so that by the intermediary of the stirrup piece 29 the blower actuating spindle 22 and the blower tube 2 are moved longitudinally. Assuming that the blower tube is initially in the rearmost, fully retracted position shown in Figure 1, 'the blower tube first advances to the foremost, fully projected position shown in Fig. 3, and then retreats until it again assumes the position shown in Fig. 1. During the forward movement, the foremost edge of the front projection 24 of the sheave-like member 23 contacts the ball 51 and moves the tappet 49 forwardly and away from the blower tube axis, as a result of which the relay valve 50 is opened, permitting steam to escape from the space 61 at one side of the piston 62. The steam pressure on the other side of the piston is thereby enabled to move the piston 62 and so open the main steam valve 21 for steam to be ejected through the nozzles of the blower head 3. The piston 62 during the last part of its movement in the valve-opening direction is cushioned by steam in the space 61 whose escape therefrom is retarded by the projection of the plunger 66 into the passage 65. During the subsequent rearward movement of the blower tube, the relay valve 50 is enabled to close under the influence of its biasing spring 54 when the projection 24 is clear of the ball 51, and when steam by leaking past the piston 62 and unable to escape has sufficiently reduced the pressure difference across the piston, the spring 67 recloses the main valve 21.

When the blower tube is in the foremost projected position the crank 13 is in a dead center position, and moreover the path of the saddle piece 29, which drives the blower tube, makes a large angle (about 40) with the axis of the blower tube, and when the blower tube is in the rearmost retracted position the crank 13 is at another dead center position and moreover the path of the saddle piece 29 also makes a large angle with the axis of the blower tube. Hence the blower tube approaches and leaves each end of its longitudinal travel quite slowly and the blower tube may be rapidly projected and retracted without undesirable sudden acceleration or deceleration, and although the blowing period lasts for a considerable portion of the cycle, the amount of longitudinal movement of the blower tube during the blowing period is small.

The worm 9 and worm wheel 12 not only constitute a S speed reduction gearing but form a simple but effective means for ensuring that the blower tube will not inadvertently gravitate towards the projected position should the soot blower be installed with the blower tube inclined downwardly.

During the cycle the rotation of the pinion effects rotation of the spur wheel and' causes the rack 31 to oscillate the actuating spindle 22 and blower tube 2 rotarily, by traversing to and fro in engagement with the secured spur wheel 32 while the guide member 37 assumes angular positions corresponding to the rack inclinations, as may be understood most readily by referring to Figs. 4 and 5. Fig. 7 illustrates the nature of the angular motion given to the blower tube by the means described. In this figure, A, B, C, D and R are points on a tube towards which the blower head 3, assumed to be at position Z, is turned at equal intervals of time, assuming that the electric motor runs at constant speed. As the blower head turns in, for example, a clockwise direction, the distances from the blower head to the tube in the directions in which the blower head faces in turning decrease from the extreme position near A at a large rate with respect to the angular positions of the blower head until about the point G is reached and during this period the angular velocity of the blower head increases, while the distances from the blower head to the tube in the directions in which the blower head faces in turning increase to the extreme position near S at a large rate with respect to the angular positions of the blower head from about when the point L is passed and during this latter period the angular velocity of the blower head decreases, whereby the speed of traversal of the jets along the tube in the parts of the tube nearer the blower head is comparatively high, whereas in the case of a blower tube rotated at constant angular velocity the speed of traversal of the jets along the tube will decrease very considerably in the parts of the tube nearer the blower resulting in much waste of steam and time.

While the steam is supplied to the blower tube, the blower tube makes two complete rotary oscillations, and it makes six rotary oscillations during one cycle of operation from the fully retracted positions to the fully projected position and back to the fully retracted position.

The total angle of oscillation of the blower tube depends upon the radial distance of the point of attachment of the rack to the spur wheel. The spur wheel is formed with a radially extending portion 72 in which, after the location of the soot blower has been chosen, the bore for the connection of the end of the rack may be formed at a radial distance dependent upon the angle over which the steam jets are desired to sweep in the chosen location of the soot blower.

It will be seen that no provision is necessary for reversing the direction of rotation of the electric motor, which once started effects projection and retraction of the blower tube and rotary oscillation of the blower tube. Normally the limit switch 48 will be arranged, after one complete cycle of operations, to effect the cuttingoff of power to the electric motor, and, when the operation of the soot blower is to be followed by the operation of the next soot blower in a series, the application of power to an electric motor of the said next soot blower.

What is claimed is:

l. A iiuid heater cleaner having a blower element arranged to be projected for operation from an inoperative or retracted position and to be rotated for the purpose of varying the direction of discharge of cleaning Huid, comprising in combination a rotatably drivable operating spindle and a rotatable and slidable blower element, rst power transmitting means for sliding the blower element and second power transmitting means for rotating the blower element, both said power transmitting means providing a continuous mechanical con- 6. nection between the spindle and the' blower' element, and both said means being actuated by continuous unidirectional rotation of the spindle to drive said blower element in two directions, said rst power transmitting means acting rst to project and then to retract the blower element during such continuing unidirectional rotation of the spindle and said second power transmitting means acting rst to rotate the blower element in one direction and then in the opposite direction during such continuous unidirectional rotation of the spindle, said second power transmitting means including a variable speed driving element adapted to impart a varying angular velocity to the blower element which reaches a maximum at approximately midway between the positions of reversal of angular rotation in order that surfaces to be cleaned more distant from the blower element may be subject to the impact of cleaning uid for longer periods of time than other surfaces nearer the blower element.

2. A tluid heater cleaner as claimed in claim l wherein the second power transmitting means includes a pinion, a crank device, and a rack connected with the crank device and in engagement with the pinion, the pinion being in driving relationship with the blower element and the blower element being axially slidable through the pinion.

3. A iiuid heater cleaner having a blower element arranged to be projected for operation from an inoperative or retracted position and to be rotated for the purpose of varying the direction of discharge of cleaning fluid, comprising in combination a rotatably drivable operating spindle and a rotatable and slidable blower element, iirst power transmitting means for sliding the blower element and second power transmitting means for rotating the blower element, both said power transmitting means providing a continuous mechanical connection between the spindle and the blower element, and both said means being actuated by continuous unidirectional rotation of the spindle to drive said blower element in two directions, said rst power transmitting means acting rst to project and then to retract the blower element during such continuing unidirectional rotation of the spindle and said second power transmitting means acting rst to rotate the blower element in one direction and then in the opposite direction during such continuous unidirectionai rotation of the spindle, said rst power transmitting means including a continuously rotatable crank, and an arm rockable thereby and operatively connected to the blower element to reciprocate the latter longitudinally in response to continuous unidirectional rotation of the crank.

4. A liuid heater cleaner having a blower element arranged to be projected for operation from an inoperative or retracted position and to be rotated for the purpose of varying the direction of discharge of cleaning iluid, comprising in combination a rotatably drivable operating spindle and a rotatable and slidable blower element, tirst power transmitting means for sliding the blower element and second power transmitting means for rotating the blower element, both said power transmitting means providing a continuous mechanical connection between the spindle and the blower element, and both said means being actuated by continuous unidirectional rotation of the spindle to drive said blower element in two directions, said rst power transmitting means acting iirst to project and then to retract the blower element during such continuing unidirectional rotation of the spindle and said second power transmitting means acting iirst to rotate the blower element in one direction and then in the opposite direction during such continuous unidirectional rotation of the spindle, a blow valve controlling the admission of blowing uid to said blower element, a substantially cylindrical abutment carried by the blower element, an actuator for the blow valve arranged in the path of travel of said abutment during reciprocation of the blower element and actuatable to srtion thereof.

References Cited in the'le of -this `patent 5 UNITED STATES PATENTS 1,161,480 Keyser Nov. 23, 1915 1,322,627 Sargent Nov. 25, 1919 1,535,495 Rawson Apr. 28, 1925 10 1,924,550 Hibner, Jr. et al. Aug. 29, 1933 8 MaeCOnvlle July 16, .1935 Wilson Oct. 13, 1942 Weeks Nov. 24, 1942 'Eves Feb. 2, -1943 FOREIGN PATENTS Great Britain Aug. 2, 19.35 Germany Feb. 23, 1929 Great 4Britain Mar. 18, 1946 

